From 4ad500087ad0db3c444acc3c8ff8cac2c231c8cf Mon Sep 17 00:00:00 2001
From: Ahmed Ibrahim <me@ahmedibrahim.dev>
Date: Wed, 4 Dec 2024 19:57:51 +0200
Subject: [PATCH] feat(models): impl. call cache

---
 packages/models/src/cache/base.ts    |  2 +-
 packages/models/src/cache/call.ts    | 67 ++++++++++++++++++++++++++++
 packages/models/src/cache/index.ts   |  3 ++
 services/server/src/handlers/call.ts |  1 -
 4 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 packages/models/src/cache/call.ts

diff --git a/packages/models/src/cache/base.ts b/packages/models/src/cache/base.ts
index 0001bd8b..3970e0e6 100644
--- a/packages/models/src/cache/base.ts
+++ b/packages/models/src/cache/base.ts
@@ -16,7 +16,7 @@ export class CacheBase {
     public client: RedisClientType<RedisModules, RedisFunctions, RedisScripts>
   ) {}
 
-  encode<T extends object>(values: T): string {
+  encode<T extends object | string | number>(values: T): string {
     return JSON.stringify(values);
   }
 
diff --git a/packages/models/src/cache/call.ts b/packages/models/src/cache/call.ts
new file mode 100644
index 00000000..cbe69129
--- /dev/null
+++ b/packages/models/src/cache/call.ts
@@ -0,0 +1,67 @@
+import { CacheBase } from "@/cache/base";
+
+export class Call extends CacheBase {
+  private readonly prefixes = {
+    call: "call",
+    user: "user:call",
+  };
+  private ttl = 60 * 60; // 1 hour
+
+  withTtl(ttl: number): Call {
+    this.ttl = ttl;
+    return this;
+  }
+
+  async addMember({ callId, userId }: { callId: number; userId: number }) {
+    const callKey = this.asCallKey(callId);
+    const userKey = this.asUserKey(userId);
+    await this.client
+      .multi()
+      .sAdd(callKey, this.encode(userId))
+      .set(userKey, this.encode(callId))
+      .expire(callKey, this.ttl)
+      .expire(userKey, this.ttl)
+      .exec();
+  }
+
+  async removeMember({ callId, userId }: { callId: number; userId: number }) {
+    await this.client
+      .multi()
+      .sRem(this.asCallKey(callId), userId.toString())
+      .del(this.asUserKey(userId))
+      .exec();
+  }
+
+  async removeMemberByUserId(userId: number) {
+    const result = await this.client.get(this.asUserKey(userId));
+    if (!result) return;
+    const callId = this.decode(result) as number;
+    await this.removeMember({ callId, userId });
+  }
+
+  async getMembers(callId: number): Promise<number[]> {
+    const result = await this.client.sMembers(this.asCallKey(callId));
+    return result.map((value) => this.decode(value));
+  }
+
+  async isMember({
+    callId,
+    userId,
+  }: {
+    callId: number;
+    userId: number;
+  }): Promise<boolean> {
+    return await this.client.sIsMember(
+      this.asCallKey(callId),
+      this.encode(userId)
+    );
+  }
+
+  private asCallKey(callId: number): string {
+    return `${this.prefixes.call}:${callId}`;
+  }
+
+  private asUserKey(userId: number): string {
+    return `${this.prefixes.user}:${userId}`;
+  }
+}
diff --git a/packages/models/src/cache/index.ts b/packages/models/src/cache/index.ts
index b26e8aca..7c3cc01d 100644
--- a/packages/models/src/cache/index.ts
+++ b/packages/models/src/cache/index.ts
@@ -3,11 +3,13 @@ import { Tutors } from "@/cache/tutors";
 import { Rules } from "@/cache/rules";
 import { RedisClient } from "@/cache/base";
 import { Peer } from "@/cache/peer";
+import { Call } from "@/cache/call";
 
 export class Cache {
   public tutors: Tutors;
   public rules: Rules;
   public peer: Peer;
+  public call: Call;
   private readonly client: RedisClient;
 
   constructor(url: string) {
@@ -16,6 +18,7 @@ export class Cache {
     this.tutors = new Tutors(client);
     this.rules = new Rules(client);
     this.peer = new Peer(client);
+    this.call = new Call(client);
   }
 
   async flush() {
diff --git a/services/server/src/handlers/call.ts b/services/server/src/handlers/call.ts
index 541a16b4..3043f831 100644
--- a/services/server/src/handlers/call.ts
+++ b/services/server/src/handlers/call.ts
@@ -2,7 +2,6 @@ import { calls } from "@litespace/models";
 import { NextFunction, Request, Response } from "express";
 import asyncHandler from "express-async-handler";
 import { withNamedId } from "@/validation/utils";
-import { groupBy } from "lodash";
 import { forbidden, notfound } from "@/lib/error";
 import { isAdmin, isGhost, isUser } from "@litespace/auth";